Contact retention device with safety stop



Jan. 11, 1966 R. A. BACHMAN 3,229,244

CDNTCT RETENTION DEVICE WITH SAFETY STOP 2 Sheecs-Shefl 1 Original Filed Sept. l, 1961 4 55 55 76 y l 4 g2 Zij/ZW INVENTOR. @055er c//Mn/v Jan. 1l, 1966 R. A. BACHMAN 3,229,244

CONTACT RETENTION DEVICE WITH SAFETY STOP Original Filed Sept. l, 1961 2 Sheets-Sheet 2 A .1&&A

INVENTGR. 0551? JQ., .Enom/,WN

BY ff//m/ .4r rae/Veys United States Patent O 3,229,244 CNTC'I RETEN'IION DEVICE WITH SAFETY STOP Robert A. Bachman, Glendale, Calif., assigner to International Telephone and Telegraph Corporation, New Yorir, N.Y., a corporation of Maryland Continuation of application Ser. No. 135,498, Sept. 1, 1961. This application Aug. 23, 1965, Ser. No. 483,025 3 Claims. (Cl. 339-217) This application is a continuation of my co-pending application, Serial No. 135,498, tiled Sept. 1, 1961, for Contact Retention Device With Safety Stop.

This invention is related to electrical components in the nature of retention clips or sleeves that, with the cooperation of insulator bodies, releasably lock electrical contact terminals captive within the insulator bodies.

A principal object of this invention is to provide a retention device in the nature of a clip or sleeve that will, with the cooperation of a body in which the retention device is lodged, releasably lock an object, such as an electrical contact terminal, captive within the body.

A further object of this invention is to provide a retention device having the foregoing characteristics wherein a plurality of resilient lingers are employed to lock the object within the body and provide structure engageable by a tool that will, when actuated, enable the object to be withdrawn from its captive condition.

A yet further object of this invention is to provide a.

retention sleeve or clip having the foregoing characteristics wherein a plurality of resilient fingers are employed to centralize and stabilize the Contact terminal within the body and at the same time provide a safety factor that will reliably protect certain other resilient lingers from being damaged or in any way having their function and operation impaired.

A more specific Object of this invention is to provide a retention clip or sleeve that is lodged in an insulator body and which has a plurality of resilient lingers, certain of which position and stabilize an electrical contact terminal in the body, and certain other resilient fingers being employed to lock the Contact terminal in the body and including structure that is engageable by a special tool such that when said structure is actuated by said tool, the locking lingers are expanded to enable the contact terminal to be withdrawn from its captive relationship.

These and other objects of the invention will become more apparent from a consideration of the description which follows, taken in conjunction with the drawings.

FIGURE 1 is a longitudinal vertical section illustrating one form of a retention clip according to the present invention lodged in an insulator body.

FIGURE 2 is a view similar to FIGURE l, and showing an electrical Contact terminal releasably locked by the retention clip and insulator body.

FIGURE 3 is a view similar to FIGURE 2, but illustrating the employment of a removal tool for releasing the electrical Contact terminal from its captive position.

FIGURE 4 is a cross sectional view taken on line 4 4 of FIGURE 2.

FIGURE 5 is a perspective view illustrating the retention clip shown in FIGURES 1-4.

FIGURE 6 is a liat pattern layout illustrating the relationship of the various components of the retention clip prior to the forming thereof.

FIGURE 7 is a view similar to FIGURE 2, but illustrating a modified form of retention clip.

FIGURE 8 is a view similar to FIGURE 3, but illustrating the use of the removal tool to release the modified form of the retention clip shown in FIGURE 7 from engagement with the electrical contact terminal.

Referring initially to FIGURES l-6, the invention comprises an insulator body 1l) having axially disposed therein a retention clip or sleeve 12 that in combination with the body releasably locks an object captive, such as an electrical Contact terminal 14. The retention clip has, generally, a split cylindrical or tubular configuration that preferably includes two sets of resilient fingers. One set of lingers, all being identical and therefore each being identified by the numeral 16, have the dual purpose of centering and stabilizing the electrical contact within the retention clip and protecting portions of the other set of lingers against damage when a special removal tool 18 is employed for removing the electrical contact. The other set of fingers, all being identical and therefore each being identified by the numeral 20, have the dual purpose of assisting in releasably locking the electrical contact terminal captive Within the retention clip and individually providing a ramp for the tool 18 when the tool is employed to remove the electrical contact terminals 14.

Merely for the purpose of orienting the various elements, to be hereinafter described in greater detail, the insulator body 1i) will be assumed to have a front or forward end 22 and a rear or back end 24.

The insulator body has a bore 26 extending therethrough which includes a cylindrical expansion cavity 28 in which the fingers 16 and 20 expand when the contact terminal 14 is inserted between the fingers and when the tool 18 is axially inserted to obtain release of the contact terminal from engagement with the lingers. The bore 26 also delines minor cylindrical cavity 3l) in the insulator body, which is in axial alignment with and partitioned from the expansion cavity by an axially spaced, inwardly projecting annular liange 31. The contact terminal 14 has an annular collar 32 thereon that is disposed in cavity 30, and under certain circumstances to be hereinafter detailed, abuts against a rearwardly facing stop shoulder 34 to limit the insertion of the Contact terminal into the insulator body and into engagement with the retention clip 12.

The flange 31 also provides a forwardly facing stop shoulder 36 the purpose of which will hereinafter become clarified.

Insertion of the retention clip 12 into the cavities 28 and 30 -is from the back 24 of the insulator body with, of course, the fingers 16 and 20 projecting axially toward the front 22.

FIGURE 6 illustrates that the linal generally split cylindrical or tubular configuration of the retention clip 12 may be produced from a flat, integral sheet of metal which includes a band 42 having parallel, alternately arranged lingers 16 and 20 extending from one side edge thereof. Although the retention clip is illustrated as produced and formed from a sheet of material, it may be cast or molded as well.

Integral with band 42 and in alignment with each linger 20 is a tap 44 that when bent outwardly in the manner illustrated in FIGURE 5 engages the stop shoulder 34: to limit the forward positioning of the retention clip 12 in bore 26.

Although tabs 44 have been described and shown, this is to be considered by way of an example only and is not to be considered a limitation. In place of tabs the retention clip may be staked, cemented or adhesively bonded in place in the insulator body 10.

Insertion of the contact terminal 14 into engagement with the lingers 16 and 20 is limited by the collar 32 engaging the tabs 44 and in the absence of tabs the collar engages the stop Shoulder 3d, as previously recited.

The band 42, concentrically disposed within the annular flange 31, is contracted by the flange to achieve an intimate and firm engagement. Additionally, when the contact terminal 14 is in its locked position, the band 42 3 encircles a cylindrical portion 46 of the contact terminal that is forward of the collar 32.

The free end of each of the fingers 16 is bent outwardly into a U-shaped hook that includes a relatively short leg 48 and a relatively long leg 50. Each leg 48 is biased, in opposition to its normal position of rest, against the wall of cavity 28 when the contact terminal is inserted into the v retention clip, and the force generated by insertion of the contact terminal 14 between fingers 16 results in effectively stabilizing and centralizing the contact terminal in the retention clip. Each leg 50 supports a cylindrical portion 52 of the terminal contact that is spaced forwardly from the cylindrical portion 46. The bight 54 of the hook functions as a safety stop to protect certain structure on fingers 20, as will hereinafter be described, when the tool 1S is inserted into cavity 28 and employed to effect release of the contact terminal 14 from its captive relationship.

The fingers 16, in the absence of contact terminal 14, are normally inclined toward the axis of the retention clip and in the forms of retention clip shown the fingers 16 are preferably lspaced approximately 120 apart. However, this is not to be considered a limitation for the rea-` son that a greater number than three fingers may be provided or for that matter a lesser number may be utilized.

Resilient fingers 20 each have a right angle bend formed therein adjacent band 42 to present a relatively short section 56 that engages stop shoulder 36. These sections 56 together with tabs 44 prevent removal of the retention clip from the insulator body 10.

A further acute angle bend is formed in each of the legs 20 at the outer edge of section 56 to provide a section 58 that is inclined forwardly and toward the axis of the retention clip and corresponds generally to the inclination of a tapered portion 60 of the contact terminal that is between cylindrical portions 46 and 52.

Each leg 20 is folded sharply back upon itself at the forward extremity of section S8, which is the position represented by the dotted line 62 in FIGURE 6, to provide a stop 64 that is engaged by a rearwardly facing shoulder 66 between the tapered portion 60 and the cylindrical portion 52 of the contact terminal 14. Withdrawal of the Contact terminal from its captive relationship between the fingers of the retention clip cannot be achieved until the stop 64 is removed from the path of engagement of shoulder 66,.

Each ofI the legs 20 is bent sharply back forwardly again at the position represented by the dotted line 67 in FlGUREv, to produce a section 68 that is generally parallel to the axis of the retention clip 12, and bears against cylindrical portion 52 of the contact terminal 14. Section 68 of each leg 20 is further bent or fiared outwardly to produce a tool-receiving ramp 70 that is inclined away from the axis of the retention clip. The extreme free end` flexing the fingers 20 outwardly until portion 52 of theV terminal is in front of the stop 64, at which time the fingers 20 will snap radially inwardly to the locking position shown in FIGURE 2. It may now be seen that the collar 3 2, abutting against tabs 44 or stop shoulder 34 limits the movement of the contact terminal in the forward direction, and rearward movement of the contact .terminal is limited by shoulder 66 engaging stop 64. It is in thisv manner that the contact terminal 14 is releasably locked in the retention clip 12.

Withdrawal of the contact terminal 14 from its captive'.

relationshipY is accomplished by theemployment of tool 18 which comprises an elongated hollow cylinder that is axially inserted into the cavity 28 from the front end 22 of the insulator body and encircles a portion of the contact terminal 14. The tool 18 engages each of the ramps 70 and the resulting radially outwardly directed force coordinate causes each of the fingers to flex or pivot about point 76 causing stops 64- to move radially y outwardly into zone 80 as shown in FIGURE 3, out of the way of the shoulder 66 on the terminal, permitting the terminal to be withdrawn from the bore 26.

As shown in FIGURE 3, the safety stops 54 limit the rearward extent of travel oftool 18, and since safety stops 54 are positioned forwardly of stops 64, the tool 18 cannot contact stops 64. In this manner, the safety stops 54 will prevent damage `from occurring t-o the now exposed stops 64.

The form of invention illustrated in FIGURES 7 and 8 y is identical to the form shown in FIGURES 1-6, except that the free end of each of the fingers 20 is bent or flared outwardly into an arcuate abutment member 86 with the concavity thereof facing forward and being engaged by the beveled end 82 of the tool 18.

The operation for expanding the ngers 20 of that form of invention illustrated in FIGURES 7 and 8 in orderV that the contact terminal 14 may be withdrawn f-rom`its captive relationship is generally similar to that previously described with respect to the form of invention illustrated in FIGURES 1 6, but has some differences. The tool 18 is inserted into the cavity 28 until the beveled end 82 engages the arcuate abutment member 86. Force applied by the tool is transmitted to each of the fingers 20 at point 88. The force coordinate perpendic- A ular to thc axis of the retention clip 12 causes each of the fingers 20 to flex or pivot about point 90, causing the stop 64 to move into zone 94, out of the path of shoulder 66 on the terminal.

The perpendicular force coordinate develops in the y following manner: The force coordinate 4parallel to the axis of the retention clip 12 causes a non-linear force between points S8 and 98 and effects a torsional effect at point 10) about point 102 and at point 102 about point 100, thus inducing a bow into both sections 58 and 68,

. causing area 104 to assume location in zone 94.

, details disclosed herein, but is to be accorded the full scope of the claims. v.

What is claimed is:

' 1. A connector unit comprising an insulation body having a -bore therethrough with a front and rear end; said bore lbeing divided into a front cavity and a rear cavity in alignment with said front cavity yand being separated therefrom by an annular wall portion that presents a front and a rear fixed stop means, the rear fixed stop means being adapted to limit` forward positioning of an elongated terminal member axially inserted into said bore from the rear; a generally split cylinder retention clip the diameter thereof being constricted when said clip is disposed in said bore to provide a secure fit; said retention clip comprising a band that is lodged inlengagement with said annular wall portion between s aid front and rear cavity; means on said band disposed so as to engage said rear fixed stop means to limit the forward positioning of said retention clip in said lbore and means on said band disposed so as to engage said front fixed stop means to limitthe rearward positioning of said retention clip; a first set of axially extending resilient fingers integral with said band in said front cavity that are adapted to axially support said terminal in said bore; a second set of resilient fingers each of which includes manipulatable stop means having a locking position adapted to limit rearward positioning of the terminal member in the bore, and a releasing position adapted to free the terminal member for rearward withdrawal out of the bore; release means integral with each of said stop means; an access passage opening forwardly of the insulation body and extending rearwardly to the release means for axial insertion of a tool from said front end to force the release means into releasing position whereby the terminal member will clear said stop means enabling the terminal to be withdrawn from the rear; and said first set of lingers being bent outwardly and real'- wardly forming a U-shaped member, the bight thereof being a safety stop positioned forward of said manipulatable stop means and engageable by said tool to limit the rearward insertion thereof into said front cavity to protect said manipulatable stop means from engagement by said tool.

2. A connector unit comprising an insulation body having a bore therethrough with a front and a rear end; a contact terminal member mounted in said bore; said bore being divided into a front cavity and a rear cavity in axial alignment with said front cavity and being separated therefrom by an annular wall portion that presents a front and a rear fixed stop, the rear fixed stop being adapted to limit forward positioning of an elongated terminal member axially inserted into said bore from the rear; a generally split cylinder retention clip the diameter thereof being constricted when said clip is disposed in said bore to provide a secure tit; said retention clip comprising a band that is lodged in engagement with said annular wall portion between said front and rear cavity; a plurality of tabs integral with said band that are bent outwardly and engage said rear fixed stop to limit the forward positioning of said retention clip in said bore; said terminal member embodying a radial projection abutting said tabs, a lirst set of resilient ngers in said front cavity and integral with said band that each include a iirst Section adjacent said band that is bent outwardly to present a shoulder that engages said front fixed stop to limit the rearward positioning of said retention clip in said front cavity; a second section integral with and forwardly of said iirst section that is inclined forwardly and toward the axis of said -bore and terminates in Va stop adapted to limit rearward positioning of the terminal member in the bore; said terminal member further embodying a tapered section and a cylindrical section immediately forward of said tapered section to produce a rearwardly facing shoulder, the cylindrical section being engageable with said inclined sections to radially cam the same outwardly upon insertion of the terminal member into the front cavity toward its final forward position, said cylindrical section being adapted to pass the inclined sections and release the stops rearwardly of said shoulder when the terminal member is in its final forward position; a third section integral with each second section and forwardly of said second section, said third section normally being flared outwardly from said second section, said third section having an arcuate terminal end with the concavity thereof facing to the front to receive a tool, and said third section including a portion bearing against the wall of the front cavity, and about which said third section pivots following engagement of the tool with said arcuate terminal end; a second set of lingers integral with said band and axially disposed in said front cavity and adapted to engage the cylindrical section of said terminal member upon passage of the cylindrical section into its iinal forward position; and an access passage opening forwardly of the insulation body that provides clearance in the front cavity for insertion of a tool between the terminal member and said third sections to force the stops radially outwardly whereby the terminal member will clear said stops to be withdrawn from the rear.

3. A connector unit comprising an insulation body llaving a bore therethrough wit-h a front and a rear end; a contact terminal member mounted in said bore; a wall portion of said bore presenting tixed stop means for limiting forward positioning of the terminal member axially inserted into the bore from the rear; resilient stop means in said bore inclined forwardly and toward the axis of said bore and having a locking position adapted to limit rearward positioning of the terminal member in the bore; said terminal member embodying an annular enlargement presenting a rearwardly facing shoulder, said enlargement being engageable with said stop means to radially cam the same outwardly upon insertion of the terminal from the rear end of the bore and said stop means being released to move radially inwardly behind said rearwardly facing shoulder on the terminal member in the final forward position of the terminal member; support means adapted to engage said annular enlargement in said final position of the terminal member; release means connected to said resilient stop means and positioned forward of said resilient stop means, said release means being flared outwardly and forwardly with respect to the axis of said bore; and an access passage opening forwardly of the insulation body that provides clearance in the forward portion of the bore for insertion of a tool ybetween the terminal member and the outwardly flared release means, said release means bearing forwardly of the ared portion thereof against the wall of said bore at a point about which said release means pivots upon the insertion of the tool into the access passage to force the resilient stop means radially outwardly whereby said rearwardly facing shoulder on the terminal member will clear said resilient stop means to permit withdrawal of the terminal member from the rear.

No references cited.

JOSEPH D. SEERS, Primary Examiner,

P, A. CLIFFORD, Assistant Examiner. 

3. A CONNECTOR UNIT COMPRISING AN INSULATION BODY HAVING A BORE THERETHROUGH WITH A FRONT AND A REAR END; A CONTACT TERMINAL MEMBER MOUNTED IN SAID BORE; A WALL PORTION OF SAID BORE PRESENTING FIXED STOP MEANS FOR LIMITING FORWARD POSITIONING OF THE TERMINAL MEMBER AXIALLY INSERTED INTO THE BORE FROM THE REAR; RESILIENT STOP MEANS IN SAID BORE INCLINED FORWARDLY AND TOWARD THE AXIS OF SAID BORE AND HAVING A LOCKING POSITION ADAPTED TO LIMIT REARWARD POSITIONING OF THE TERMINAL MEMBER IN THE BORE; SAID TERMINAL MEMBER EMBODYING AN ANNULAR ENLARGEMENT PRESENTING A REARWARDLY FACING SHOULDER, SAID ENLARGEMENT BEING ENGAGEABLE WITH SAID STOP MEANS TO RADIALLY CAM THE SAME OUTWARDLY UPON INSERTION OF THE TERMINAL FROM THE REAR END OF THE BORE AND SAID STOP MEANS BEING RELEASED TO MOVE RADIALLY INWARDLY BEHIND SAID REARWARDLY FACING SHOULDER ON THE TERMINAL MEMBER IN THE FINAL FORWARD POSITION OF THE TERMINAL MEMBER; SUPPORT MEANS ADAPTED TO ENGAGE SAID ANNULAR ENLARGEMENT IN SAID FINAL POSITION OF THE TERMINAL MEMBER; RELEASE MEANS CONNECTED TO SAID RESILIENT STOP MEANS AND POSITIONED FORWARD OF SAID RESILIENT STOP MEANS, SAID RELEASE MEANS BEING FLARED OUTWARDLY AND FORWARDLY WITH RESPECT TO THE AXIS OF SAID BORE; AND AN ACCESS PASSAGE OPENING FORWARDLY OF THE INSULATION BODY THAT PROVIDES CLEARANCE IN THE FORWARD PORTION OF THE BORE FOR INSERTION OF A TOOL BETWEEN THE TERMINAL MEMBER AND THE OUTWARDLY FLARED RELEASE MEANS, SAID RELEASE MEANS BEARING FORWARDLY OF THE FLARED PORTION THEREOF AGAINST THE WALL OF SAID BORE AT A POINT ABOUT WHICH SAID RELEASE MEANS PIVOTS UPON THE INSERTION OF THE TOOL INTO THE ACCESS PASSAGE TO FORCE THE RESILIENT STOP MEANS RADIALLY OUTWARDLY WHEREBY SAID REARWARDLY FACING SHOULDER ON THE TERMINAL MEMBER WILL CLEAR SAID RESILIENT STOP MEANS TO PERMIT WITHDRAWAL OF THE TERMINAL MEMBER FROM THE REAR. 